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Objectives: To clarify the usefulness of molecular biomarkers for distinguishing invasive carcinoma derived from intraductal papillary mucinous neoplasms (IPMNs [Inv-IPMN]) from concomitant pancreatic ductal adenocarcinoma (PDAC)., Methods: Data from 19 patients with resected concomitant PDAC were retrospectively reviewed. KRAS/GNAS mutations and immunohistochemical (IHC) expression of p53 and p16/CDKN2A were assessed in both IPMN and distinct PDAC. As controls, KRAS/GNAS mutations and IHC labeling were assessed between invasive and noninvasive components in 1 lesion of 22 independent patients., Results: KRAS/GNAS mutation status of invasive and noninvasive components in Inv-IPMN was consistent in 18 (86%) of 21 patients. Conversely, mutational patterns in IPMN and distinct PDAC in the same pancreas differed from each other in 17 (89%) of 19. There were 10 (53%) and 8 (42%) of 19 patients who showed the same p53 and p16/CDKN2A staining between concomitant PDAC and distinct IPMN. In the Inv-IPMN cohort, 19 (86%) of 22 patients showed the same IHC expression pattern between the noninvasive and invasive components., Conclusions: It may be possible to distinguish Inv-IPMN from concomitant PDAC by assessing these molecular biomarkers. More precise distinction of Inv-IPMN and concomitant PDAC will lead to adequate recognition of the natural history of IPMNs and hence optimal management.

The cell surface protein Transmembrane 4 L6 family member 1 (TM4SF1) has been detected in various tumors, and its expression on tumor cells is implicated in cancer cell metastasis and patient prognosis. The role of TM4SF1 in malignant tumors remains poorly understood, particularly in pancreatic cancer. We performed immunohistochemical staining to analyze the expression of TM4SF1 in resected pancreatic tissues and investigated the correlation between TM4SF1 expression and prognosis. The function of TM4SF1 in the invasion and migration of pancreatic cancer cells was analyzed in vitro using an RNA interference technique. In pancreatic cancer tissues, TM4SF1 expression was detected in cancer cells, and patients with high tumor levels of TM4SF1 showed longer survival times than those with low TM4SF1 levels (P=0.0332). In vitro, reduced TM4SF1 expression enhanced the migration (P<0.05) and invasion (P<0.05) of pancreatic cancer cells partially via decreased E-cadherin expression. TM4SF1 protein levels were also reduced after TGF-β1-induced epithelial-mesenchymal transition (EMT).TM4SF1 expression is associated with better prognosis in pancreatic cancer. Loss of TM4SF1 contributes to the invasion and migration of pancreatic cancer cells.

Objective: The aims of this study were to investigate the GNAS mutational status in pancreatic intraductal papillary mucinous neoplasm (IPMN) with and without distinct pancreatic ductal adenocarcinoma (PDAC) and to evaluate the significance of GNAS analysis using duodenal fluid (DF) in patients with IPMN., Methods: The clinicopathologic features of 110 patients with IPMN including 16 with distinct PDAC were reviewed. The GNAS status in the IPMN tissue and 23 DF specimens was assessed by sensitive mutation scanning methods., Results: The GNAS mutation rate in IPMN with distinct PDAC was significantly lower than that in IPMN without PDAC (4/16, 25%, vs 61/94, 65%; P = 0.0047). By multivariate analysis, GNAS wild-type and gastric type IPMNs were significantly associated with distinct PDAC. Of 45 GNAS wild-type IPMNs, 10 (43%) of 23 gastric type IPMNs had distinct PDAC, whereas only 2 (9%) of 22 non-gastric type IPMNs had distinct PDAC (P = 0.017). The GNAS status in DF was consistent with that in tissue in 21 (91%) of 23 patients., Conclusions: Distinct PDACs frequently develop in the pancreas with gastric type IPMN without GNAS mutations. Duodenal fluid DNA test would predict the GNAS status of IPMN, whereas the detection of the gastric subtype using noninvasive test remains to be determined.

Anterior gradient 2 (AGR2), a member of the protein disulfide isomerase family, has been implicated in various cancers including pancreatic ductal adenocarcinoma (PDAC) and is known to promote cancer progression. However, the prognostic value of AGR2 expression and the interaction with epithelial-mesenchymal transition (EMT) remain unclear. We investigated the clinical significance of AGR2 and EMT markers in PDAC patients by immunohistochemical analyses. Although AGR2 expression was not observed in normal pancreas, all pancreatic precursor neoplastic lesions were positive for AGR2, even at the earliest stages, including pancreatic intraepithelial neoplasia-1A, AGR2 expression was reduced in 27.7% (54/195 cases) of PDAC patients. AGR2 downregulation correlated with EMT markers (vimentin overexpression and reduced membranous E-cadherin expression), high Union for International Cancer Control stage (P<0.0001), high histological cellular grade (P<0.0001), and adverse outcome (P<0.0001). In vitro, targeted silencing of AGR2 in cancer cells using siRNA reduced cell proliferation, colony formation, cell invasiveness, and migration, but did not alter EMT markers. To confer a more aggressive phenotype and induce EMT in PDAC cells, we co-cultured PDAC cell lines with primary-cultured pancreatic stellate cells (PSCs) and found that AGR2 was downregulated in co-cultured PDAC cells compared with PDAC monocultures. Treatment with transforming growth factor beta-1 (TGF-β), secreted from PSCs, decreased AGR2 expression, whereas inhibition of TGF-β signaling using recombinant soluble human TGF-β receptor type II and TGF-β-neutralizing antibodies restored AGR2 expression. We conclude that AGR2 downregulation is a useful prognostic marker, induced by EMT, and that secreted TGF-β from PSCs may partially contribute to AGR2 downregulation in PDAC patients. AGR2 downregulation does not induce EMT or a more aggressive phenotype, but is a secondary effect of these processes in advanced PDAC.

Background: CD166, also known as activated leukocyte cell adhesion molecule (ALCAM), is expressed by various cells in several tissues including cancer. However, the role of CD166 in malignant tumors is controversial, especially in pancreatic cancer. This study aimed to clarify the role and significance of CD166 expression in pancreatic cancer., Methods: We performed immunohistochemistry and flow cytometry to analyze the expression of CD166 in surgical pancreatic tissues and pancreatic cancer cell lines. The differences between isolated CD166+ and CD166- pancreatic cancer cells were analyzed by invasion and migration assays, and in mouse xenograft models. We also performed quantitative RT-PCR and microarray analyses to evaluate the expression levels of CD166 and related genes in cultured cells., Results: Immunohistochemistry revealed high expression of CD166 in pancreatic cancer tissues (12.2%; 12/98) compared with that in normal pancreas controls (0%; 0/17) (p = 0.0435). Flow cytometry indicated that CD166 was expressed in 33.8-70.2% of cells in surgical pancreatic tissues and 0-99.5% of pancreatic cancer cell lines. Invasion and migration assays demonstrated that CD166- pancreatic cancer cells showed stronger invasive and migratory activities than those of CD166+ cancer cells (p<0.05). On the other hand, CD166+ Panc-1 cells showed a significantly stronger colony formation activity than that of CD166- Panc-1 cells (p<0.05). In vivo analysis revealed that CD166+ cells elicited significantly greater tumor growth than that of CD166- cells (p<0.05) in both subcutaneous and orthotopic mouse tumor models. mRNA expression of the epithelial-mesenchymal transition activator Zeb1 was over-expressed in CD166- cells (p<0.001). Microarray analysis showed that TSPAN8 and BST2 were over-expressed in CD166+ cells, while BMP7 and Col6A1 were over-expressed in CD166- cells., Conclusions: CD166+ pancreatic cancer cells are strongly tumorigenic, while CD166- pancreatic cancer cells exhibit comparatively stronger invasive and migratory activities. These findings suggest that CD166 expression is related to different functions in pancreatic cancer cells.

Background: Pancreatic cancer is associated with a devastating prognosis, partially because of its aggressive metastatic ability. Identification of prognostic markers of metastasis would be useful in the clinical management of postoperative patients with pancreatic cancer. Mal, T-cell differentiation protein 2 (MAL2) has been identified as a molecule predictive of metastases; the clinical relevance of MAL2 in pancreatic cancer is unknown., Methods: Orthotopic human pancreatic cancer xenografts from the pancreatic cancer cell line SUIT-2 were established in nude mice. Only liver metastasis was harvested and cultured. These metastatic cycles were repeated 5 times to establish a highly metastatic cell line, termed metastatic SUIT-2 (MS). We investigated proliferation and motility of MS cells compared with those of the parent SUIT-2. Microarray analysis was performed to investigate differences in gene expression. We also performed immunohistochemical analysis of 89 formalin-fixed, paraffin-embedded human pancreatic cancer tissue samples to investigate the clinical significance of MAL2 expression., Results: MS cells showed a greater metastatic rate after orthotopic implantation than parental SUIT-2. MS cells had increased motility but decreased proliferation compared with parental SUIT-2. Microarray analyses showed that 26 genes were significantly upregulated (>10-fold) in MS cells compared with parental SUIT-2, particularly MAL2 expression. Immunohistochemical analysis showed that high expression of MAL2 was associated with a lesser survival of postoperative patients (P = .03) and a high rate of distant metastasis (P = .008)., Conclusion: We characterized a newly established pancreatic cancer cell line with highly metastatic potential. MAL2 is a promising predictive marker for distant metastasis and short survival in patients with resected pancreatic cancer., (Copyright © 2013 Mosby, Inc. All rights reserved.)

Background: Pancreatic cancer (PC), a hypovascular tumor, thrives under hypoxic conditions. Pancreatic stellate cells (PSCs) promote PC progression by secreting soluble factors, but their functions in hypoxia are poorly understood. This study aimed to clarify the effects of hypoxic conditions on the interaction between PC cells and PSCs., Methods: We isolated human PSCs from fresh pancreatic ductal adenocarcinomas and analyzed functional differences in PSCs between normoxia (21% O2) and hypoxia (1% O2), including expression of various factors related to tumor-stromal interactions. We particularly analyzed effects on PC invasiveness of an overexpressed molecule-connective tissue growth factor (CTGF)-in PSCs under hypoxic conditions, using RNA interference techniques., Results: Conditioned media from hypoxic PSCs enhanced PC cell invasiveness more intensely than that from normoxic PSCs (P < 0.01). When co-cultured with PSCs, PC cell invasion was more enhanced under hypoxia than under normoxia (P < 0.05). Among various soluble factors, which were related to invasiveness, CTGF was one of the overexpressed molecules in hypoxic PSCs. A higher level of CTGF expression was also found in supernatant of hypoxic PSCs than in supernatant of normoxic PSCs. PC cell invasiveness was reduced by CTGF knockdown in hypoxic PSCs co-cultured with PC cells (P < 0.05)., Conclusion: Hypoxia induces PSCs' secretion of CTGF, leading to enhancement of PC invasiveness. CTGF derived from hypoxia-stimulated PSCs may be a new therapeutic target for pancreatic cancer., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objectives: Kindlin-2 is a novel focal adhesion protein reported to be expressed in breast, lung, and gastric cancers. This study aimed to investigate the significance of kindlin-2 expression in pancreatic ductal adenocarcinomas (PDACs)., Methods: We performed immunohistochemical analysis on kindlin-2 on PDAC samples from 95 patients. We investigated the association between kindlin-2 expression and clinicopathological parameters of PDAC and the survival time of patients with PDAC who underwent pancreatectomy., Results: Kindlin-2 was highly expressed in the peritumoral stroma of PDACs. Stromal kindlin-2 expression was related to nodal metastasis (P = 0.03). Univariate analysis showed that patients with positive kindlin-2 expression had significantly shorter survival times than those with negative kindlin-2 expression (P = 0.01). In addition, multivariate analysis revealed that kindlin-2 expression was an independent factor of poor prognosis in patients with PDAC after R0 resection (RR = 2.15; P = 0.04)., Conclusions: Kindlin-2 expression in stromal components is significantly associated with poor prognosis of patients with PDAC, suggesting that kindlin-2 is a prognostic marker for patients with PDAC.

Objectives: The aim of this study was to establish a minimally invasive and simple screening test for detection of pancreatic ductal adenocarcinoma (PDAC) using duodenal juice (DJ)., Methods: Duodenal juice was collected prospectively before endoscopic retrograde cholangiopancreatography in 46 patients. A protease inhibitor was not added to the samples collected during the initial 2.5 minutes but was added in the latter 2.5 minutes. Thereafter, secretin was administered intravenously, and DJ was subsequently collected for additional 10 minutes. The sensitivities of carcinoembryonic antigen (CEA), S100 calcium-binding protein P (S100P), and interleukin 8 in DJ and pancreatic juice were assessed., Results: There were 30 patients with PDAC and 16 with benign lesions. It was possible to collect an adequate amount of DJ without secretin administration. In the PDAC group, CEA concentrations in DJ were significantly higher than those in the benign group, even without the use of a protease inhibitor. S100P levels in DJ in the PDAC group were significantly higher than those in the benign group in the presence of the protease inhibitor., Conclusions: Duodenal juice collection during routine upper endoscopy and assessments of CEA and S100P in DJ might become a useful screening test for detection of PDAC.

Background: Identification of prognostic markers would be useful in the clinical management of patients with pancreatic ductal adenocarcinoma (PDAC). The clinical relevance of claudin-4 (CLDN4), recently identified as overexpressed in PDAC, is unknown., Methods: Using quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR), we analyzed CLDN4 mRNA expression in a panel of 9 pancreatic cancer cell lines and formalin-fixed paraffin-embedded (FFPE) tissues from 100 patients with PDAC. The CLDN4 expression levels were then correlated with clinicopathological variables and patient outcome. We also performed immunohistochemical analysis in 20 FFPE samples of PDAC to investigate the expression of CLDN4 protein., Results: Increased expression of CLDN4 was confirmed in all the pancreatic cancer cell lines tested compared with normal ductal epithelial cells and fibroblasts. We found that low expression of CLDN4 was significantly associated with shorter survival in patients with PDAC (hazard ratio; 1.362, 95% confidence interval; 1.011-1.873, P = 0.0419). Patients with high CLDN4 expression survived longer for a median of 63.0 months, compared with 14.7 months in patients with low CLDN4 expression (P = 0.0067). In immunohistochemical analysis, the level of CLDN4 mRNA expression was significantly correlated with the expression of CLDN4 protein (P = 0.0168)., Conclusion: Increased expression of CLDN4 mRNA predicts better prognosis in PDAC.

Background: There is increasing evidence that microRNAs are differentially expressed in many types of cancers. Despite progress in analyses of microRNAs in several types of cancers, the functional contributions of microRNAs to pancreatic cancer remain unclear., Methods: In the present study, the expression levels of specific microRNAs identified by microarray analyses were examined in a panel of 15 pancreatic cancer cell lines. We then investigated the functional roles of these microRNAs in the proliferation and invasion of pancreatic cancer cells., Results: Based on the microarray data, we found frequent and marked overexpression of miR-10a, miR-92, and miR-17-5p in pancreatic cancer cell lines. Microdissection analyses revealed that miR-10a was overexpressed in pancreatic cancer cells isolated from a subset of primary tumors (12 of 20, 60%) compared with precursor lesions and normal ducts (P<.01). In vitro experiments revealed that miR-10a inhibitors decreased the invasiveness of pancreatic cancer cells (P<.01), but had no effect on their proliferation. Inhibition of HOXA1, a target of miR-10a, promoted the invasiveness of pancreatic cancer cells (P<.01)., Conclusions: The present data suggest that miR-10a is overexpressed in a subset of pancreatic cancers and is involved in the invasive potential of pancreatic cancer cells partially via suppression of HOXA1.

Background: To improve the prognosis of patients after resection of pancreatic cancer, the most appropriate and efficient treatment should be provided to specific subsets of patients. Our aim was to identify promising microRNAs as markers to predict responses to gemcitabine in patients with resected pancreatic cancer., Methods: Two gemcitabine-resistant pancreatic cancer cell lines were established, and global microRNA expression analyses was performed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Eleven miRNAs were selected as putative predictive markers and analyzed by means of macrodissected formalin-fixed, paraffin-embedded samples obtained from 90 patients with or without gemcitabine treatment after resection of pancreatic cancer., Results: We identified 24 microRNAs whose expression was altered in gemcitabine-resistant cells. qRT-PCR analyses showed that patients with high miR-142-5p and miR-204 expression had significantly longer survival times than those with low miR-142-5p (P = 0.0077) and miR-204 (P = 0.0054) expression in the gemcitabine-treated group. This was not seen in the nontreated group. Multivariate analyses showed that miR-142-5p expression was an independent prognostic marker only in patients treated with gemcitabine (P = 0.034)., Conclusions: miR-142-5p is a promising predictive marker for gemcitabine response in patients with resected pancreatic cancer.

Claudin-4, encoding a protein for tight junction formation and function, is highly overexpressed in pancreatic ductal adenocarcinoma and is also associated with invasive adenocarcinomas arising in intraductal papillary mucinous neoplasms of the pancreas. However, the expression pattern of claudin-4 during neoplastic progression of intraductal papillary mucinous neoplasms remains unknown. Using quantitative real-time reverse transcription-PCR, we analyzed claudin-4 mRNA in a panel of 14 pancreatic cancer cell lines and in formalin-fixed paraffin-embedded tissues from 80 patients with intraductal papillary mucinous neoplasms of different histological grades and papillary subtypes. Increased expression of claudin-4 was confirmed in all the pancreatic cancer cell lines tested as compared with normal ductal epithelial cells and fibroblast cultures. The claudin-4 expression was significantly higher in high-grade intraductal papillary mucinous neoplasms (borderline neoplasm and carcinoma) than in low-grade intraductal papillary mucinous neoplasms (adenoma) (P<0.0001). In addition, claudin-4 mRNA levels were significantly higher in intestinal-type intraductal papillary mucinous neoplasms than in non-intestinal-type intraductal papillary mucinous neoplasms based on papillary subclassification (P<0.0001). Our findings suggest that claudin-4 expression is associated with neoplastic progression of intraductal papillary mucinous neoplasms and, especially, with a distinct pathway to intestinal differentiation.

Background: Detection of aberrant microRNA (miR) expression may contribute to diagnosis and prognosis of various cancers. The aim of this study is to evaluate the correlation between miR-203 expression and prognosis of patients with pancreatic adenocarcinoma after curative resection., Methods: A total of 113 formalin-fixed paraffin-embedded tissue samples of pancreatic adenocarcinoma, 20 samples of chronic pancreatitis, and 8 samples of normal pancreas were obtained. We investigated the association of miR-203 expression measured by quantitative reverse-transcription polymerase chain reaction assays with clinicopathological parameters and survival times., Results: miR-203 was overexpressed in pancreatic adenocarcinoma samples compared with chronic pancreatitis (P < 0.001) and normal pancreas (P = 0.001) samples. An association between miR-203 expression and clinicopathological factors of pancreatic adenocarcinoma was not observed. On univariate analysis, the high-miR-203 group and the subgroup (20%) of cases with the highest miR-203 overexpression had significantly shorter survival time (P = 0.048 and P = 0.024, respectively). Multivariate analysis revealed that miR-203 expression was an independent predictor of poor prognosis in cases with no residual tumor (relative risk 2.298, P = 0.027)., Conclusions: miR-203 expression is a new prognostic marker in pancreatic adenocarcinoma patients.

Background and Aims: The standard palliative chemotherapy for pancreatic ductal adenocarcinoma (PDAC) is gemcitabine-based chemotherapy; however, PDAC still presents a major therapeutic challenge. The aims of this study were to investigate the expression pattern of genes involved in gemcitabine sensitivity in resected PDAC tissues and to determine correlations of gene expression with treatment outcome., Materials and Methods: We obtained formalin-fixed paraffin-embedded (FFPE) tissue samples from 70 patients with PDAC. Of the 70 patients, 40 received gemcitabine-based adjuvant chemotherapy (AC). We measured hENT1, dCK, CDA, RRM1, and RRM2 messenger RNA (mRNA) levels by quantitative real-time reverse transcription-polymerase chain reaction and determined the combined score (GEM score), based on the expression levels of hENT1, dCK, RRM1, and RRM2, to investigate the association with survival time. By determining the expression levels of these genes in endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) cytologic specimens, we investigated the feasibility of individualized chemotherapy., Results: High dCK (P = .0067), low RRM2 (P = .003), and high GEM score (P = .0003) groups had a significantly longer disease-free survival in the gemcitabine-treated group. A low GEM score (<2) was an independent predictive marker for poor outcome to gemcitabine-based AC as shown by multivariate analysis (P = .0081). Altered expression levels of these genes were distinguishable in microdissected neoplastic cells from EUS-FNA cytologic specimens., Conclusions: Quantitative analyses of hENT1, dCK, RRM1, and RRM2 mRNA levels using FFPE tissue samples and microdissected neoplastic cells from EUS-FNA cytologic specimens may be useful in predicting the gemcitabine sensitivity of patients with PDAC.

Intraductal papillary mucinous neoplasms of the pancreas are subclassified based on morphological features, and different immunohistochemical profiles have been identified in association with the subtypes. We previously reported that S100P was an early developmental marker of pancreatic carcinogenesis and that there was higher S100P expression in intraductal papillary mucinous neoplasms than in normal pancreatic ductal epithelium. However, there have been no reports on novel diagnostic markers to distinguish intraductal papillary mucinous neoplasm from nonneoplastic lesions. Surgical specimens of intraductal papillary mucinous neoplasm obtained from 105 patients were investigated using immunohistochemistry. S100P expression was not detected in normal pancreatic ductal epithelium but was detected in all intraductal papillary mucinous neoplasm cells (100%) with diffuse nuclear or nuclear/cytoplasmic staining. MUC5AC was also expressed in most of the intraductal papillary mucinous neoplasms (102/105; 97%). Furthermore, S100P was clearly expressed in the invasive component of intraductal papillary mucinous neoplasms (32/32; 100%), including perineural and lymphatic and minimal invasion. On the other hand, MUC5AC was expressed in only 23 cases of 32 invasive components (P < .01). These data suggest that the S100P antibody may be a useful marker for detecting all types of intraductal papillary mucinous neoplasms., (Copyright 2010 Elsevier Inc. All rights reserved.)

Objective: The aim of this study is to evaluate the clinical significance of S100A4 mRNA expression in pancreatic cancer., Materials and Methods: We obtained invasive ductal carcinoma (IDC) cells from ten lesions, intraductal papillary mucinous neoplasm (IPMN) cells from 20 lesions, and normal ductal cells from 20 normal pancreatic tissues by laser microdissection of frozen tissues. S100A4 expression was examined in the microdissected cells and in formalin-fixed paraffin-embedded (FFPE) samples of 87 pancreatic cancers by quantitative reverse transcription-polymerase chain reaction., Results: IDC cells expressed higher levels of S100A4 than IPMN cells (P = 0.002) and normal ductal cells (P < 0.001), although the difference between IPMN cells and normal ductal cells was not statistically significant (P = 0.070). Analysis of FFPE samples revealed that high S100A4 expression was significantly associated with a shorter overall survival (P = 0.023). In immunohistochemical analysis, the extent of S100A4 mRNA expression was significantly correlated with the expression of S100A4 protein (P = 0.028)., Conclusion: S100A4 could be a marker for malignancy in pancreatic tumors and for poor prognosis in patients with pancreatic cancer.

Purpose: LIM domain only 2 (LMO2) has been identified as a novel oncogene associated with carcinogenesis and better prognosis in several malignant tumors. We investigate the involvement of LMO2 in pancreatic cancer., Experimental Design: We evaluated LMO2 expression in cultured cells, bulk tissues, and microdissected cells from pancreatic cancers by quantitative reverse transcription-polymerase chain reaction and immunohistochemistry., Results: Of 164 pancreatic cancers, 98 (60%) were positive for LMO2 expression. LMO2 was more frequently detected in high-grade pancreatic intraepithelial neoplasia (PanIN) lesions (PanIN-2 and -3) than in low-grade PanIN lesions (PanIN-1A and -1B; P < .001) and was not detected in normal pancreatic ductal epithelium. The LMO2 messenger RNA levels were significantly higher in invasive ductal carcinoma cells than in normal pancreatic cells as evaluated by quantitative reverse transcription-polymerase chain reaction analyses of microdissected cells (P = .036). We also found higher incidence of LMO2 expression in histologic grade G1/G2 cancers than in grade G3 cancers (P < .001). The median survival time of LMO2-positive patients was significantly longer than that of LMO2-negative patients (P < .001), and multivariate analyses revealed that high LMO2 expression was an independent predictor of longer survival (risk ratio, 0.432, P < .001). Even among patients with a positive operative margin, LMO2-positive patients had a significant survival benefit compared with LMO2-negative patients. We further performed a large cohort study (n = 113) to examine the LMO2 messenger RNA levels in formalin-fixed paraffin-embedded samples and found similar results., Conclusions: LMO2 is a promising marker for predicting a better prognosis in pancreatic cancer.

Purpose: Midkine (MK) has been reported to be a possible molecular marker for the diagnosis of pancreatic cancer. We investigated the feasibility of quantitative analysis of MK mRNA by quantitative real-time RT-PCR (qRT-PCR) as a promising tool for the diagnosis of pancreatic cancer., Results: We found that pancreatic cancer tissues expressed significantly higher levels of MK mRNA than intraductal pancreatic mucinous neoplasm (IPMN) and non-neoplastic pancreatic tissues (P < 0.05); in contrast, we did not find any differences in MK mRNA expression between IPMN and non-neoplastic pancreatic tissues. Additionally, we observed that poorly differentiated carcinoma samples expressed higher levels of MK mRNA than well-differentiated carcinoma samples, although a significant difference was not observed., Conclusions: The present data suggests that quantitative analysis of MK mRNA provides an objective and sensitive evaluation and may be a promising modality for the diagnosis of pancreatic cancer and the prediction of its prognosis.

Recent microarray analyses showed that the S100 family contains members that are candidate diagnostic markers or therapeutic targets. In the present study, to evaluate the involvement of S100A6 in pancreatic cancer and its clinical usefulness for diagnosis, we examined S100A6 mRNA expression in pancreatic tissues and pancreatic juice from patients with different pancreatic diseases. To investigate the role of S100A6 in carcinogenesis of pancreatic cancer and the potential of S100A6 as a diagnostic marker for early detection of pancreatic cancer, we did immunohistochemistry and microdissection-based mRNA analysis of pancreatic normal ducts, pancreatic intraepithelial neoplasias, and invasive ductal carcinomas. We also used in vitro experiments and microarray analysis with RNA interference to evaluate the functional role of S100A6 and its potential as a therapeutic target for pancreatic cancer. S100A6 mRNA levels were significantly higher in carcinoma specimens than in nonneoplastic tissues. In pancreatic juice, there was a significant difference in S100A6 expression between patients with carcinoma and those with nonneoplastic disease. Receiver operating characteristic curves revealed that S100A6 might be a useful marker for diagnosis of pancreatic cancer. Immunohistochemistry and microdissection-based analysis showed differential expression of S100A6 among normal ducts, pancreatic intraepithelial neoplasias, and invasive ductal carcinomas. In vitro data showed that inhibition of S100A6 decreased proliferation and invasiveness of cancer cells, and these findings were supported by microarray data. Our present results suggest that quantitation of S100A6 mRNA is a promising tool for diagnosis of pancreatic cancer, and that S100A6 may be a promising therapeutic target for pancreatic cancer.

Objectives: Telomerase is highly activated in a variety of malignant neoplasms including colon cancer. Among the major components of telomerase, human telomerase reverse transcriptase (hTERT) is thought to regulate telomerase activity. To assess the importance of telomerase for the diagnosis of colorectal cancer, we measured the expression of hTERT mRNA and telomerase activity in a large series of 140 colorectal cancers, 140 adjacent normal tissues, and 20 adenomas., Methods: The expression level of hTERT was measured quantitatively by competitive reverse transcriptase-polymerase chain reaction (RT-PCR), and telomerase activity was examined by telomeric repeat amplification protocol (TRAP) assay in the same samples., Results: The median expression level of hTERT mRNA in carcinomas was significantly higher than that in either adenomas or normal tissues. The median level of hTERT in adenomas was significantly higher than that in normal tissues. Telomerase activities in carcinomas were significantly higher than those in either adenomas or normal tissues. Telomerase activities in adenomas were also significantly higher than those in normal tissues. Furthermore, the relative expression levels of hTERT mRNA in adenomas and carcinomas were significantly correlated with the relative telomerase activities; the Spearman rank correlation was 0.53 (p = 0.021) and 0.18 (p = 0.031), respectively., Conclusions: Our data suggest that determination of hTERT mRNA by competitive RT-PCR is superior in quantitative accuracy and sensitivity and would support the importance of telomerase activity for the diagnosis of colorectal cancer.

Background: Telomerase activity has been reported to have potential as a useful diagnostic marker for cancer in various organs. The authors previously reported that telomerase activity in pancreatic juice differentiates pancreatic ductal carcinoma from adenoma and pancreatitis. In the current study, the usefulness of semiquantitatively determined telomerase activity in the diagnosis of malignant biliary tract neoplasms was investigated., Methods: The samples examined included 61 surgically resected biliary tract tissues (11 gallbladder carcinomas, 5 bile duct carcinomas, 1 gallbladder adenoma, 30 cholecytitis cases, 7 cholesterol polyps, 1 normal gallbladder, and 6 normal common bile duct tissues), 42 bile samples from patients with biliary tract or pancreatic disease (19 cases of malignant biliary tract disease, 11 cases of benign biliary tract disease, 10 cases of malignant pancreatic disease, and 2 cases of benign pancreatic disease), and 14 bile duct biopsy specimens collected by percutaneous transhepatic choledochoscopy or endoscopic retrograde cholangiopancreatography (8 bile duct carcinoma specimens, 1 bile duct adenoma specimen, and 5 hepatolithiasis specimens)., Results: In biliary tract tissues, a telomerase ladder was detected in 73% of gallbladder carcinomas, 40% of bile duct carcinomas, and none of the other biliary tract tissues. One gallbladder adenoma showed a weak telomerase ladder. The telomerase ladder was detected in the bile sample from 1 patient (5.3%) with malignant biliary tract disease, none of the patients with benign biliary tract disease, 5 patients (50%) with malignant pancreatic disease, and none of the patients with benign pancreatic disease. In biopsy specimens, the telomerase ladder was detected in 75% of patients with bile duct carcinoma but not in any of the patients with hepatolithiasis. The median value of relative telomerase activity in the patients with bile duct carcinoma was significantly higher than that in the patients with hepatolithiasis. The diagnosis of bile duct carcinoma was confirmed preoperatively by histopathologic examination in only 25% of the biopsy specimens., Conclusions: The results of the current study indicate that telomerase is highly activated in biliary tract carcinomas and that the detection of a telomerase ladder in biopsy samples is an excellent tool for the diagnosis of bile duct carcinomas.

We report a patient with pancreatic cancer in whom telomerase activity had been detected in the pancreatic juice 19 months before he was diagnosed as having pancreatic cancer. A 61-yr-old alcoholic man complaining of epigastric and back pain was diagnosed as having groove pancreatitis based on the presence of inflammation in the pancreatic head and its extension to the duodenal mucosa with an associated elevated serum amylase level. All imaging modalities showed no sign of a tumor. However, high telomerase activity was detected in the pancreatic juice collected during endoscopic retrograde pancreatography. His symptoms subsided due to abstinence from alcohol. A tumor, however, was recognized on computed tomography 19 months later, at which time the patient immediately underwent a pylorus-preserving pancreaticoduodenectomy. The carcinoma was located mainly in the Santorini duct region. High telomerase activity in the pancreatic juice may precede clinical detection of pancreatic cancer and thus could be a useful early diagnostic marker for pancreatic cancer.

Pancreatic tumor antigen (PTA) was purified to apparent homogeneity from hamster pancreatic adenocarcinomas by a rapid and simple procedure using column chromatography on Mono P and Superose 6. Amino acid analysis indicated essential similarities between hamster PTA and human pancreatic cancer-associated antigen (PCAA, PCAAc), although differences in the contents of several amino acid residues between the two proteins did suggest species variation. Investigation of the binding pattern of antibody raised against PTA by peroxidase-labeled antibody immunocytochemistry revealed that, whereas PTA is absent or only faintly expressed in normal epithelium, it is very strongly positive in transplantable hamster pancreatic adenocarcinomas induced by nitrosamines. PTA was found to be distributed over the entire surface of neoplastic cells and it was concluded that the presence of PTA on the basolateral surface of malignant pancreatic epithelial cells, where it might have access to the blood circulation, could be one explanation for the observed elevated concentrations of PTA in the serum. PTA is thus a potential marker for hamster neoplastic pancreatobiliary duct-type cells.